1. Field of the Invention
The present invention relates to compositions which comprise surface-modified nanoscale solid particles with groups having active hydrogen or precursors thereof, preferably hydroxyl groups and/or epoxy groups, and at least one optionally blocked isocyanate compound, and to coatings and molded bodies which are preparable from these compositions and are cured to form urethane bonds or corresponding bonds.
2. Discussion of Background Information
Abrasion-resistant layers with high optical transparency for optical components or high-transparency layers on optical components have become an important field of investigation. Nanocomposite coatings based on sol-gel processes, in which organosilanes are cocondensed together with nanoparticles and form hard layers, have been found to be significant. When silanes which contain polymerizable groups (methacrylates or epoxides) are used, such layers may also be UV-curable and photostructurable. However, the disadvantage of such coatings is the lack of UV stability and also the insufficient scratch resistance associated with high brittleness.
It would therefore desirable to be able to provide coatings or moldings which have high transparency and additionally exhibit high attrition resistance.